Lubricants are generally employed in various metal working operations and fabrications. Such operations include rolling, forging, blanking, bending, stamping, drawing, cutting, punching, spinning, bending, stretch forming, extruding, coining, hobbing, swaging, and the like. In the automotive and appliance fields, the term "stamping" is used as a broad term to cover all press working operations on sheet metal, which operations may be further categorized as cutting, drawing, or coining.
Metal working or fabricating lubricants, particularly dry film lubricants, facilitate these operations by reducing friction between the metal being worked and the tooling employed for that process. This reduces power required for a particular operation, reduces wear on the surfaces of tooling that operate on metals, and prevents sticking between metal being worked and tooling operating thereon, or between metal pieces during storage, handling and operations. A dry film lubricant can further provide corrosion prevention properties to metal being worked and tooling metal. In automotive and appliance applications, prevention of sticking between metal pieces and between such pieces and work elements is of extreme importance. In aerospace and airplane applications it is of extreme importance to fabricate metal pieces without signs of seizing or galling.
In some metal working processes, including automotive and appliance applications, coils or rolls of steel, in particular cold rolled or galvanized steel sheets, are cut into pieces, called blanks, which are stamped or drawn to produce desired parts. Such automotive parts, formed by stamping or drawing, include fenders, hoods, deck lids, quarter panels, oil pans, fuel tanks, floor panels, inner and outer door panels, and the like. Appliance parts, formed by stamping and drawing, include washer tops, dryer tops, washer and dryer fronts, top and front lids, dryer tumblers and the like. Prior to use of a dry film lubricant, normal procedures were to apply an oil at the mill (e.g., steel mill) to such coils and rolls as a rust preventative prior to shipping to the processing site. Before the metal forming operation, rust preventative oil is removed and a dry film lubricant is added.
More recently, use of rust preventative oils has declined and dry film lubricants are applied directly at the steel mill to act as both a lubricant and as a rust preventative agent. Such agents, now in use in automotive and appliance industries, are hydrocarbon based compositions containing sulfurized or waxy components. Such agents are generally liquid at ambient room temperature. These compositions tend to drain off the metal surfaces, creating maintenance problems and further tend to be or become unevenly distributed on metal surfaces due to capillary forces. Properties of rust prevention and drawing frictional reduction both depend, in large part, on uniformity of lubricant films. A tendency to puddle on a metal surface diminishes a lubricant's potential for providing protection from rust and in reducing friction during a fabricating or forming operation. Moreover, greater and more uniform friction reduction properties over the entire metal surface will permit more severe fabricating and forming process to occur without signs of seizing or galling. Further, with current hydrocarbon-based compositions, housekeeping and cleanliness are difficult to maintain because such compositions leak onto tooling surfaces, contaminate floor trenches and waste treatment streams, volatilize into air and create dermatitis problems on a worker' s skin.
Further, metal working operations, such as metal tube bending or stretch forming requires an extreme pressure lubricant that is in a paste form and can be applied manually or mechanically to tubes and the like. An extreme pressure lubricant should be capable of being removed from the metal once the tube bending or stretch forming operation is completed. Moreover, it is desirable to be able to dispose of the lubricant as a non-hazardous waste.
Therefore, there is a need in the art for a dry film lubricant that can eliminate or reduce many of these problems.